When the dirty_log_test is run nested, due to very slow nature of
the environment, it is possible to reach a situation in which no entries were
harvested from the dirty ring and that breaks the test logic.
Detect this case and just let the guest run a bit more until test obtains
some entries from the dirty ring.
Signed-off-by: Maxim Levitsky <mlevitsk@xxxxxxxxxx>
---
tools/testing/selftests/kvm/dirty_log_test.c | 25 +++++++++++++-------
1 file changed, 17 insertions(+), 8 deletions(-)
diff --git a/tools/testing/selftests/kvm/dirty_log_test.c b/tools/testing/selftests/kvm/dirty_log_test.c
index f60e2aceeae0..a9428076a681 100644
--- a/tools/testing/selftests/kvm/dirty_log_test.c
+++ b/tools/testing/selftests/kvm/dirty_log_test.c
@@ -227,19 +227,21 @@ static void clear_log_create_vm_done(struct kvm_vm *vm)
vm_enable_cap(vm, KVM_CAP_MANUAL_DIRTY_LOG_PROTECT2, manual_caps);
}
-static void dirty_log_collect_dirty_pages(struct kvm_vcpu *vcpu, int slot,
+static bool dirty_log_collect_dirty_pages(struct kvm_vcpu *vcpu, int slot,
void *bitmap, uint32_t num_pages,
uint32_t *unused)
{
kvm_vm_get_dirty_log(vcpu->vm, slot, bitmap);
+ return true;
}
-static void clear_log_collect_dirty_pages(struct kvm_vcpu *vcpu, int slot,
+static bool clear_log_collect_dirty_pages(struct kvm_vcpu *vcpu, int slot,
void *bitmap, uint32_t num_pages,
uint32_t *unused)
{
kvm_vm_get_dirty_log(vcpu->vm, slot, bitmap);
kvm_vm_clear_dirty_log(vcpu->vm, slot, bitmap, 0, num_pages);
+ return true;
}
/* Should only be called after a GUEST_SYNC */
@@ -350,7 +352,7 @@ static void dirty_ring_continue_vcpu(void)
sem_post(&sem_vcpu_cont);
}
-static void dirty_ring_collect_dirty_pages(struct kvm_vcpu *vcpu, int slot,
+static bool dirty_ring_collect_dirty_pages(struct kvm_vcpu *vcpu, int slot,
void *bitmap, uint32_t num_pages,
uint32_t *ring_buf_idx)
{
@@ -373,6 +375,10 @@ static void dirty_ring_collect_dirty_pages(struct kvm_vcpu *vcpu, int slot,
slot, bitmap, num_pages,
ring_buf_idx);
+ /* Retry if no entries were collected */
+ if (count == 0)
+ return false;
+
cleared = kvm_vm_reset_dirty_ring(vcpu->vm);
/*
@@ -389,6 +395,7 @@ static void dirty_ring_collect_dirty_pages(struct kvm_vcpu *vcpu, int slot,
}
pr_info("Iteration %ld collected %u pages\n", iteration, count);
+ return true;
}
static void dirty_ring_after_vcpu_run(struct kvm_vcpu *vcpu, int ret, int err)
@@ -424,7 +431,7 @@ struct log_mode {
/* Hook when the vm creation is done (before vcpu creation) */
void (*create_vm_done)(struct kvm_vm *vm);
/* Hook to collect the dirty pages into the bitmap provided */
- void (*collect_dirty_pages) (struct kvm_vcpu *vcpu, int slot,
+ bool (*collect_dirty_pages)(struct kvm_vcpu *vcpu, int slot,
void *bitmap, uint32_t num_pages,
uint32_t *ring_buf_idx);
/* Hook to call when after each vcpu run */
@@ -488,7 +495,7 @@ static void log_mode_create_vm_done(struct kvm_vm *vm)
mode->create_vm_done(vm);
}
-static void log_mode_collect_dirty_pages(struct kvm_vcpu *vcpu, int slot,
+static bool log_mode_collect_dirty_pages(struct kvm_vcpu *vcpu, int slot,
void *bitmap, uint32_t num_pages,
uint32_t *ring_buf_idx)
{
@@ -496,7 +503,7 @@ static void log_mode_collect_dirty_pages(struct kvm_vcpu *vcpu, int slot,
TEST_ASSERT(mode->collect_dirty_pages != NULL,
"collect_dirty_pages() is required for any log mode!");
- mode->collect_dirty_pages(vcpu, slot, bitmap, num_pages, ring_buf_idx);
+ return mode->collect_dirty_pages(vcpu, slot, bitmap, num_pages, ring_buf_idx);
}
static void log_mode_after_vcpu_run(struct kvm_vcpu *vcpu, int ret, int err)
@@ -783,9 +790,11 @@ static void run_test(enum vm_guest_mode mode, void *arg)
while (iteration < p->iterations) {
/* Give the vcpu thread some time to dirty some pages */
usleep(p->interval * 1000);
- log_mode_collect_dirty_pages(vcpu, TEST_MEM_SLOT_INDEX,
+
+ if (!log_mode_collect_dirty_pages(vcpu, TEST_MEM_SLOT_INDEX,
bmap, host_num_pages,
- &ring_buf_idx);
+ &ring_buf_idx))
+ continue;
/*
* See vcpu_sync_stop_requested definition for details on why
--
2.26.3
